The invention relates particularly to concrete molding machines having molds which are vibrated to densify the concrete mix in the molds. Machines of this character utilize molds which are open at their upper and lower ends and are supported in the machine in a manner to accommodate their vibration. The lower ends of the molds are normally closed by pallets which are supported on a pallet receiver which is movable up to cause the pallet to close the lower end of the mold and to lift it slightly from its mold frame supports and support it for vibration. The pallet receiver frame is provided with resilient members which support the pallet and isolate the vibration. Following charging of a concrete mix to the upper end of the mold and vibration of the mold to compact the wet concrete mix material in the mold, a stripper head is moved downwardly through the mold cavity simultaneously with movement of the pallet receiver downwardly to strip the molded product from the mold. In today""s high production machines, the entire cycle may be completed in a matter of seconds.
Molding machinery of this general character is well known and disclosed, for example, in the present assignee""s U.S. Pat Nos. 3,545,053; 4,235,580; and 5,952,015, all of which I incorporate herein by reference. Also incorporated herein by reference, is U.S. Pat. No. 4,941,813, which depicts a mold guidance system used on some of the present assignee""s machines, as well as another version thereof. Also know is a mold lock system wherein each vertical guide pin on which the mold moves up and down in its vibration can be moved in one lateral direction by a horizontal adjustment screw carried by one of the mold side bars. Bearing pads are provided between the screw and mold side bar and between the frame and mold side bar in lateral alignment with the screw and are referred to respectively as the front mold lock liner and the mold throat liner. To my knowledge, all such pin systems which guide the mold when it is vibrating require manual unfastening and refastening manipulation when molds are to be changed.
During the operation of such machines, a number of different products are normally manufactured on the machine in production runs of various duration, and the molds must be changed to produce such differing concrete products. Molds of this type for producing relatively heavy concrete products, such as concrete blocks, are very large and may weigh in the neighborhood of 4,000 pounds. When a mold is to be changed, present machines require the manual removal of pins and any associated changing mechanisms from the mold to be replaced before it can be moved out of the machine, and then the manual reassembly of such mechanism after a replacement mold is transferred to the machine, before the machine can be placed into operation again.
The improved machine of the present invention provides powered mechanism for automatically removing the mold guidance pins from operating position to enable the mold to be transferred out of the machine and a replacement mold to then be placed in the machine without impediment.
In the method of practicing the present invention, remotely energized powered mechanism removes mold alignment members downwardly out of the path of the mold from a locked position in which they function as alignment pins for the mold during the vibration cycle and restrain and dampen the lateral components of vibration. Then, after replacement of the mold, the guidance members are automatically replaced with the act of simply energizing the powered member.
One of the prime objects of the present invention is to provide an improved concrete product molding machine which requires much less machine downtime for changeover of the molds.
Another object of the invention is to provide a high production, concrete product molding machine incorporating guidance mechanism which speeds up the product producing process.
A further object of the invention is to provide a durable, heavy duty machine which adequately restrains and dampens lateral components of the vibration.
Still another object of the invention is to provide such a machine with an improved mold guidance mechanism that effectively resists the application of excessive vibratory loads to the machine frame which progressively cause the metal fatigue and failure of parts of the frame and mold, and the consequent costs involved in replacement and machine downtime.
Still another object of the invention is to provide a pin guidance system which automatically locks in position and is not dependent upon human efficiency in the refastening of guidance pins.
Still another object of the invention is to provide an improved machine in which the mold is not as rigidly laterally restrained and mold wear is substantially reduced with the result that the molds will have a longer operational life.
Still another object of the invention is to provide a machine which produces quality concrete blocks and other concrete products in a rapid and efficient manner.
Other objects and advantages of the invention will become apparent with reference to the accompanying drawings and the accompanying descriptive matter.